基于热网络分区等效策略的Si/SiC混合器件耦合热参数辨识方法  

Enhanced Identification Approach for RC Parameters of Si/SiC Hybrid Switches Based on Thermal Network Partition Scheme

作　　者：龙柳 肖凡[1] 涂春鸣[1] 肖标 郭祺[1] Long Liu;Xiao Fan;Tu Chunming;Xiao Biao;Guo Qi(National Electric Power Conversion and Control Engineering Technology Research Center,Hunan University,Changsha,410082,China)

机构地区：[1]国家电能变换与控制工程技术研究中心(湖南大学),长沙410082

出　　处：《电工技术学报》2024年第12期3718-3731,共14页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金重点资助项目(52130704)。

摘　　要：由硅(Si)绝缘栅双极型晶体管(IGBT)与碳化硅(SiC)金属氧化物半导体场效应晶体管(MOSFET)并联构成的混合器件可打破单一Si基器件和SiC基器件的局限性,实现损耗和成本间的有效均衡。结温估计对于Si/SiC混合器件的可靠运行至关重要,然而,目前针对热监测的研究往往需满足热稳态平衡和功率损耗可测两大条件,在实际变流器中实用性较低。基于此,该文以零输入响应法为切入点,首先,对Si/SiC混合器件热结构特性进行分析,详细阐述零输入响应法直接应用于混合器件时所带来的高阶热约束条件难以表征的问题;其次,通过对SiIGBT与SiC MOSFET进行热网络分区处理实现模型的降阶,构建出壳温降温曲线时间常数与热参数之间的约束关系,提出了基于热网络分区等效思想的混合器件耦合热参数辨识方法,所提方法简化了功率损耗测量步骤与热平衡态条件,在并联器件耦合热参数辨识研究中具有简单、通用、流程化高的应用优势;最后,通过实验验证了该文所提方法的准确性和有效性。The hybrid switch with paralleled Si IGBT and SiC MOSFET can break the limitations of single Si-based and SiC-based devices and effectively balance loss and cost.Junction temperature estimation is crucial for the reliable operation of Si/SiC hybrid switches.However,research on thermal monitoring often needs to meet two major conditions:thermal steady-state balance and measurable power loss.This paper proposes a coupling thermal parameter identification method for hybrid switches utilizing the thermal network partition equivalence concept.The accurate identification of the coupled thermal network parameters can be realized by only three case temperature cooling curves.Firstly,the thermal structure characteristics of Si/SiC hybrid switches are analyzed,and the challenge of high-order thermal constraints when the zero-input response method is directly applied to a hybrid switch is elaborated.Secondly,the thermal network partition of Si IGBT and SiC MOSFET is carried out to reduce the order of the model.According to Kirchhoff's law and node voltage equation,the Laplace expressions of Si IGBT and SiC MOSFET case temperatures are obtained.Thirdly,based on the mathematical relationship between the root and the coefficient,the constraint equations between the time constant of the case temperature cooling curve and the thermal parameters are constructed.By simultaneously solving the equations under the thermal network partition equivalence,all the remaining thermal parameters can be identified.Finally,the hybrid switch’s coupling thermal parameter identification process is designed.In this process,the experimental steps of thermal time constant extraction are simple,greatly reducing the difficulty of solving the thermal constraint equations.Based on the experimental platform,the time constants of the cooling curves under two heat dissipation conditions are fitted,and all RC parameters can be solved by substituting the fitted time constants into the thermal constraint equations.Compared with the junction-to-case thermal

关 键 词：耦合热参数辨识 Si/SiC混合器件 热网络分区 热时间常数 热约束 

分 类 号：TM46[电气工程—电器]